Laser Excited Atomic Fluorescence Spectrometry (LEAFS) is potentially the best available technique for the determination of trace metals in samples from the points of view of both sensitivity and accuracy. Detection limits have been reported for furnace LEAFS that are the best of any analytical technique to date. It is proposed to develop Analytical Instrumentation which is designed to exploit the potential of LEAFS for the determination of trace metals in samples related to the study of metal toxicology. The benefits of improvement in sensitivity will be a decrease in the amount of sample required, which could lead to the more efficient use of live animals, and the ability to avoid solvent extraction techniques which reduces the risk of contamination of samples and reduces analysis time. The accuracy of furnace LEAFS has not been explored in a rigorous fashion. This proposal addresses the accuracy problem by exploring the use of Zeeman effect background correction to compensate for spectral interferences, and a rapidly heated carbon furnace to minimize volatilization interferences. Further, optimization of the geometrical shape and size of the furnace, and the use of rapid furnace heating, should give improved sensitivities of metal determinations over those already reported for furnace LEAFS. Ultimately the objective is to find out whether or not the features of furnace LEAFS, improved sensitivity and accuracy over current techniques, have been realized, and whether or not hit erto difficult trace metal toxicological research becomes feasible. Manganese, lead and tin will serve as models for evaluating furnace LEAFS.